Imagine a cool valley with a cluster of blue pools strung together like a necklace of diamonds. At the end of the valley, a spring behind the highest pool bubbles continuously to create a resonance that is refreshing and relaxing. This peaceful place is Black Dragon Pool (hēi lóng tán 黑龙潭), located in a 220-meter high, 4-kilometer long valley, which is in the northwestern Lupiguan (lù pí guān 鹿皮关) of the Shicheng Town (shí chéng xiāng 石城乡) in Miyun (mì yún 密云), 100 kilometers away from Beijing. The valley is commonly called Gulu Valley (gū lù yù
轱辘峪), because of its steepness. There are three waterfalls and eighteen pools in the valley. It is always appraised as being fresh, astonishing and steep.

Black Dragon Pool Scenic Spot is a Grade 4A scenic spot and not far from Miyun Reservoir (mì yún shuǐ kù 密云水库). This deep and serene valley boasts many unique scenic spots each with its own character. The thrill of watching the rushing water and the steep waterfalls make this Black Dragon Pool special. The narrow meandering paths, which visitors can hike along, ladders and bridges provide a sense of adventure and achievement. On some of the pools, visitors can also row rubbertán boats while breathing in the scents of wild grass and flowers.

It is an erosion-type pool scenic spot formed by streams flowing in the valleys, also called Wheel Valley, it is winding and twisting, with steep cliffs on both sides. In fact, there are many attractions in this area, and the Black Dragon Pool is only one of them. A lot of waterfalls and pools are located in this only four-kilometer valley, which is rare in and outside Beijing. Everywhere can give people a fresh feeling from the beginning to the end of the journey. You will feel relaxed and happy, just as if you were in a fairyland.

The most famous one is Black Dragon Pool. It is only four to five square meters in acreage but 25.6 meters in depth, which is the deepest pool known in Beijing. The walls around the pool are smooth. On the south side, the pool is in oval shape, while the north part has steep cliffs. The water drops vertically from the cliffs more than 10 meters high. There is a narrow gap in the middle of the cliffs, less than one meter in width, and tens of meters in length. There are also two small pools in the narrow gap like two shy girls, hidden in their boudoirs. One is called "Spring Flower Pool (chūn huā tán 春花潭)", and another is called "Autumn Moon Pool (qiū yuè tán 秋月潭)". If the tourists would like to see the panorama of the pools, they have to wait until the spring and autumn.

Tongtian Fall (tōng tiān pù 通天瀑) is another astonishing sight. The cliffs are vertical and steep, as if being cut by knives. The falls are flying down with a height drop of more than 50 meters, with splashing water and fog pervasive in the valley.
Since 1985, activities such as talking walks in spring, seeking coolness in summer, picking fruits in autumn and ice climbing in winter, are held every year, which have attracted many tourists.